Impact-engine



W. A. SMITH. .IMPACT ENGINE.

Arrucmon man vc.26. 19:1.

Patented Apr. 27," 1920.

nnrTnD sTnTEs PATENT orsi-or..

WILLIAM A. SMITH, 0F DENVER, CQLDRADO, ASIGNR INGERSOLL-RAND COMPANY,`OF JERSEY CITY, NEW JERSEY, GRPORATEON OF NEW JERSEYv IMPACT-ENGINE.

i Specification of Letters Patent.

lratented Apr. 27, 1920.

.Application` filed December 26, 1917. Serial No. 208,755.

if' 10 all y207mm t may concern l-o it known that I, WILLIAM A. SMITH, ay citizen of the United States, residing at Denver, in the county of Denver and State of Colorado, have invented certain new and useful Improvements in lmpact-lilngines. v of which the following is a specification.

invention relates to improvements in impact engines of the type in which a reciprocating hammer or piston is operated by fluid pressure to deliver a rapid succession of blows upon a cutting tool at the front end of a housing in which the piston has its movement.

It is the primary object of the present invention to provide a novel method. of admitting the compressed air or other motive fluid used in the operation of the impact engine, to the working faces of its reciprocating piston and of exhausting the same at the proper periods, whereby to obtain the maximum efficiency in ratio'to the impelling force of the motive fluid.

l attain this object by the construction and arrangement of parts shown in the accompanying drawings in theV two views of which corresponding parts are designated by like reference characters, and in which- Figure 1 represents a longitudinal section of my improved impact engine with the piston at the beginning of its active, forward stroke, and

Fig. 2, a similar section'with .the piston in the position it occupies at the time it comes in impellent engagement with the cutting tool at the forward end of the housing in which it has its movement.

In the drawings, the reference numeral 2 designates the housing of the impact engine, 3 the piston or hammer which has a reciprocating movement therein, and 4 the cutting tool which is longitudinally slidably fitted in a keeper 5 at the front end of the housing, and projects within the same to be engaged by the piston during its active stroke.

The housing has a piston-way composed of a primary pressure chamber 8 intermediate of two end-chambers 6 and 7 of reduced diameter.

The piston of the impact-engine is composed Vof an oblong body, the end portions lof which provide heads 9 and 10 which are slidingly fitted in the end chambers of the piston-way.

- The pistonhas intermediate of its ends,

an integral head 12 of enlarged diameter which is fitted for reciprocation in the primary pressure chamber and it has between its said end-portions and its enlarged head, annular grooves 13 and lil` which provide channels for the passage of motive fluid to the different chambers, as will hereinafter be more fully described.

The channels of the piston are spaced from the head 12 to provide at opposite sides thereof, shoulders 1.5 and 16 which upon entering the end chambers of the piston-way at the ends of the piston-strokes, produce aircushions to deaden the impact of the parts.

The chamber 6 of the piston-way at the forward end. ofthe housing opens into an enlarged closed space 17 into which the rear end of the cutting tool projects, and serves in the operation of the engine to guide the forward portion of the piston in its reciprocating motion to and from the tool.

The chamber 7 at the rear end of the housing` which 'will hereinafter be referred to as the auxiliary pressure-chamber, is adapted to communicate directly withl the atmosphere by an exhaust port18 and a therewith connecting annular groove instead of indi-` rectly through one of the other working chambers in the tool, and the primary pressure-chamber 8 connects with the atmosphere by means of an independent exhaust port 19 which likewise is connected with an annular depressionin the chamber-wall to expedite the direct discharge of spent fluid.

The air or other fluid *under pressure 'used in the operation of the engine, enters the housing through an inlet 20 which by means of passages 21 and 22 is in continuous communication with ports 23 and 24 in the 'end-chambers of the piston-way adjacent nect with annular grooves in the chamberwalls to expedite and facilitate the passage of motive-fluid.

The exhaust-port 19 of the primary pressure-chamber@ is located so as to connect alternately with the spaces of the chamber at opposite sides of the piston-head 12 during the reciprocating movement of the piston, and the exhaust-port 18 of the auxiliary pressure-chamber 7 is covered by the respective end-portion 10 of the piston until the piston nears the end of its forward stroke at which it engages the cutting-tool as shown in Fig. 2 of the drawings.

At the linish of the idle piston stroke, the ports 23 and 25 are in register with the rearward piston-channel 13 to admit motive fluid simultaneously at corresponding ends of the primary and auxiliary piston-chambers, as shown in Fig. l of the drawings. A

When the piston approaches the end of its active stroke, these ports .are covered by the head 10, and the channel 1-/1 comes in register with the forward admission-port 211 to admit motive fluid to the space of the primary pressure-chamber forward of the head 12, for the return movement of the piston.

With the piston in this position the exhaust-port 18 of the auxiliary pressure-- chamberv is uncovered and the independent exhaust-port 19 communicates with the space of the primary pressure-chamber rearward of the piston-head 12,

In the operation of the engine,'air under pressure, or other motive-fluid, enters the housing through the inlet 20.

Premising that the piston is at the beginning of its forward Vor active stroke, as shown in Fig. 1, the channel 13 of the piston connects the admission-port 25 with the piston chamber 8 and with the port 23 to admit motive fluid simultaneously tothe rear end of the primary pressure-chamber and, by means of the by-pass 27, to the correspondingend of the auxiliary pressure chamber.

The exhaaist-port 18 of the auxiliary pressure-chamber is at the same time covered by the respective end-portion of the piston and the exhaust port of the large piston-chamber communicates with the space thereof forward of the piston-head 12.

The piston is driven forwardly by the pressure of the motive-fluid thus admitted to its working Afaces at the corresponding ends of the heads 12 and 10, until its rear end-portion uncovers the exhaust-port 18 and its head 12 has moved past the exhaust port 19, at which time the ports 23 and 25 are covered by the head 10, and the forward admission-port 24 is placed in communica.- tion with the forward end of the primary pressure-chamber by registration with the piston-channel 14.

The piston after having reached this position continues its forward motion by its inertia until the forward shoulder V15 enters the guide-'chamber 6, at which point its motion is reversed by the action of the compressed fluid in the forward portion of the large pressure-chamber upon the forward working face of the piston-head 12.l

Y At the end of each stroke of the piston,

the rearward shoulder 16 momentarily entersthe rear pressure-chamber 7 thereby providing an air-cushion in the rearward space of the large chamber auxiliary to that simultaneously produced in the other pressure-chamber.

Having thus described my invention what I claim and Patent is: Y

1. An impact-engine comprising a housing having primary and auxiliary pistonchambers, ports for the admission of motive fluid at corresponding ends thereof and independent ports in said chambers for the exhaust of fluid directly from said chambers, and a tool-operating piston in said housing having working faces in said chambers and controlling the fluid-passage through said admission and exhaust ports, the piston being adapted to establishV communication between the chambers and the.

respective exhaust-ports at the finish of its active stroke and to uncover the admission ports at the finish of its idle stroke for the admission of Huid to the chambers.

2. An impact-engine comprising a housing having primary and auxiliary pistonchambers, ports for the admission of motive-fluid at corresponding ends thereof and independent ports in said chambers for the exhaustrof fluid directly from said chambers, and a tool-operatingpiston'i'nfsaid housing having working-faces ins'aid chambers and controlling the Yfluid-passage through said admission and exhaust ports, thepiston being adapted to establish communication between the chambers and the respective exhaust ports at the finish of itsV active stroke and to uncoverthe admissionportsat the finish of its idle stroke for the admission of fluid to the chambers, andthe piston Yhaving a shoulder which cushions the idle stroke by entering theauxiliary piston-chamber.

3. An impact-engine comprising a housing having primary and auxiliary piston chambers, ports for the admission of motive fluid at opposite ends of the primary chamber, `a port for the admission of motive fluid at one end of the auxiliary chamber and ports for the exhaust of fluid from the chambers, and a tool-operating piston in the housing, having a piston-headin the primary ehamber and Yan auxiliary'working face in the auxiliary chamber and controlling the fluid-passage through saidports,

said piston being adapted to *uncover the ports for the admission of motive fluid at corresponding ends of the chambers at the finish of its idle stroke, to cover said ports and uncove1 the Vport for the admission of fluid at the other end of the primary chamber at the finish of its active stroke, to

simultaneously uncover the exhaust-port of the auxiliary chamber and to p alternately place the exhaust port of the primary chamdesire to secure by Letters- Y of the larger chamber and adapted to beuncovered by the piston at the finish of its active stroke for the exhaust of fluid from said chamber, and a separate exhaust port for said larger chamber. Y

5. The combination with an impact-engine in which a piston has working faces Vin two chambers of different diameters, and controls the passage of motive-fluid through ports connecting with said chambers, of a passage uncovered by the piston at the finish of its idle stroke for the admission offluid at an end of the smaller chamber, a port in said smaller chamber independent of the larger4 chamber and adapted to be uncovered by the piston at the finish of its active stroke for the exhaust of fluid from said. chamber, a shoulder on the piston which cushions the idle stroke of the piston by entering said smaller chamber, and a separate exhaust port for said larger chamber.

GK fin impact-engine comprising a housing having primary and auxiliary piston chambers, a port in connection with a fluid-inlet to admit motive-fluid at an end of the primary chamber, a 1passage for the admission of' fluid at the corresponding end ofthe auxil- 'ary chamber and independent ports in said chambers for the exhaust of fluid directly from the chambers, and a tool-operating piston having piston-heads working in said chambers, and between said heads, a channel which coperates with the heads to control the fluid passage through said ports, said channel connectincr said admission-port with the primary chamber and with said passage for the simultaneous admission of motive fluid at corresponding sides of the piston-heads at the finish of the idle pistonstroke, and the head in the auxiliary chamber uncovering the independent exhaust port for said chamber at the finish of the active piston stroke.

7. An impact-engine comprising a housing having a primary piston-chamber, a piston-guide chamber and an auxiliary piston chamber respectively at opposite ends thereof, a fluid-inlet, ports connected therewith for the admission of fluid at opposite ends of' the primary chamber, a passage to admit liuid at an end of the auxiliary chamber, and independent ports in said chambers for bers,

the exhaust of fluid directly from the chamanda piston having heads working in said chambers land between said heads, chalinels which coperate `with the heads to control the fluid-passage through said ports, the channel between the heads in the primary and auxiliary piston-chambers connecting -one of said admission-ports with an end of the primary chamber and with said passage for the simultaneous admission of fluid at corresponding ends of said chambers at the finish of the idle piston-stroke, andthe channel between the head in the primary chamber and the head in the guide-chamber connecting the other admission-port with the Vopposite end of the primary chamber at the finishof the active piston-stroke while the piston-head in the auxiliary piston-chamber uncovers the independent exhaust-port for said chamber.

8. An impact-engine comprising a housing having primary and auxiliary piston chambers, a port in connection with a fluidinlet to admit motive-fluid at an end of the primary chamber, a passage for the admission of fluid at the corresponding end of the auxiliary chamber and ports for the exhaust of fluid from the chambers, and a tool-operating piston having piston-heads working in said chambers, and between said heads a channel which coperates with the heads to control the fluid-passage through said ports, said channel connecting said admission-port with the primary chamber and with said passage for the simultaneous admission -of motive fluid at corresponding sides of the piston-heads at the finish of the idle pistonstroke, and the head in the auxiliary chamber uncovering the respective exhaust port at the finish of the active piston-stroke, there being a shoulder between said channel and the head in the primary chamber which cushions the idle stroke of the piston by entering the auxiliary piston-chamber at the finish of said stroke.

9. An impact engine comprising a housing having a primary piston-chamber, respectively at opposite ends thereof a pistonguide-chamber and an auxiliary piston-v chamber, a fluid-inlet, ports connected therewith for the admission of fluid at opposite ends of the primary chamber, a passage to admit fluid at an end of the auxiliary chamber, and independent ports in said chambers for the exhaust of fluid directly from the chambers, and a piston having heads working in said chambers and between said heads, channels which coperate with the heads to control the fluid-passage through said ports, the channel between the heads in the primary and auxiliary piston-chambers connecting one of said admission-ports with an end of' the ,primary chamber and with said passage for the simultaneous admission of fluid at corresponding ends of said cham- Vbers at the finish of' the idle piston-stroke,

and the channel between the head in the primary chamber and the head in the guide chamber connecting the other admission-port with the opposite end of the primary chamber at the finish of the active piston-stroke While the piston-head in the auxiliary piston-chamber uncovers the independent exhaust-port for said chamber, there being shoulders at opposite sides of the head in the primary chamber which cushions the piston-strokes by entering the other chambers at the finish of the same.

second admission-port adjoining the firstnientioned port, a by-pass connecting the second portwith an end of the auxiliary chamber, and separate ports for the exhaust of fluid from the chambers, and a piston having heads Working in said chambers and between said heads7 a channel which cooperates with the heads to control the fluid-passage through Vsaid ports, said channel connecting the first-admission-port With the primary chamber and with the second admission-port for the simultaneous admission of: motive fluid at corresponding sides off the pistonheads at the finish of the idle piston-stroke l and the head in the auxiliary chamber uncovering its respective exhaust-port at the finish of the active piston-stroke. p

In testimony whereof. I have affixed my signature. f

WILLIAM A. SMITH. 

